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Simatic S7 Cpu 1200 FirmwareOperating system · Siemens

CVE-2014-2256

HIGH · 7.8 CVSS v2.0 Published 2014-03-24
Fix available
A fix is available. Upgrade to after 3.0.2 or later.
See remediation →
87/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Siemens SIMATIC S7-1200 CPU PLC devices with firmware before 4.0 allow remote attackers to cause a denial of service (defect-mode transition) via crafted ISO-TSAP packets, a different vulnerability than CVE-2014-2257.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Siemens SIMATIC S7-1200 CPU PLC devices with firmware versions prior to 4.0 contain a denial of service vulnerability. Remote attackers can send specially crafted ISO-TSAP packets to trigger a defect-mode transition, causing the PLC to enter an unresponsive or fault state.

MitigationUpdate SIMATIC S7-1200 firmware to version 4.0 or later to remediate this vulnerability. In the interim, restrict network access to PLC management interfaces using firewalls or VLANs to limit exposure to unauthenticated ISO-TSAP packets.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Simatic S7 Cpu 1200 FirmwareOperating system
Affected:<= 3.0.2= 3.0
Simatic S7 Cpu 1211cHardware / appliance
Affected:all versions
Simatic S7 Cpu 1212cHardware / appliance
Affected:all versions
Simatic S7 Cpu 1214cHardware / appliance
Affected:all versions
Simatic S7 Cpu 1215cHardware / appliance
Affected:all versions
Simatic S7 Cpu 1217cHardware / appliance
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:L/Au:N/C:N/I:N/A:C

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the PLC model
    Locate the model number printed on the PLC physical label or check in the TIA Portal project properties under 'Device overview' for the CPU type (e.g., SIMATIC S7-1200, 1211c, 1212c, 1214c, 1215c, or 1217c)
    Affected if The model is any of: S7-1200 CPU, 1211c, 1212c, 1214c, 1215c, or 1217c - all are listed as affected
  2. Check the firmware version
    In TIA Portal, go to Online > Online and diagnostics > Diagnostics > General, or access the PLC via web server at 'http://<PLC_IP>' and view the version under 'Device information'. For S7-1200 base CPU, also check the label on the device.
    Affected if The firmware version is 3.0 or 3.0.2 or lower for S7-1200 CPU; for 1211c/1212c/1214c/1215c/1217c, all versions are affected regardless of number
  3. Verify network exposure to ISO-TSAP
    Check firewall rules, VLAN configuration, or network segment that the PLC's Ethernet/Profinet interface is connected to. Confirm whether ports 102 (ISO-TSAP) or other engineering access ports are reachable from untrusted networks.
    Affected if The PLC is accessible on the network and ISO-TSAP packets can reach it from an untrusted segment
  4. Inspect PLC operational status
    Connect via TIA Portal or physical HMI and check if the PLC is in RUN mode, STOP mode, or DEFECT/Fault state. Also check the diagnostic buffer for entries indicating sudden fault or defect-mode transition.
    Affected if The PLC has entered DEFECT mode or shows frequent fault states with no other explanation
  5. Review recent network traffic
    Capture network traffic on the PLC's interface or review logs from any network monitoring device (IDS/IPS, firewall) for unusual ISO-TSAP packets or high volume of malformed packets targeting port 102
    Affected if There are logs or captures of malformed or suspicious ISO-TSAP packets reaching the PLC

You are affected if your PLC is any of the S7-1200, 1211c, 1212c, 1214c, 1215c, or 1217c models with firmware 3.0.2 or lower (or any version for the C suffix models), and it is reachable on the network via ISO-TSAP.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 3.0.2
Interim mitigation

Update SIMATIC S7-1200 firmware to version 4.0 or later to remediate this vulnerability. In the interim, restrict network access to PLC management interfaces using firewalls or VLANs to limit exposure to unauthenticated ISO-TSAP packets.

Fix this in Simatic S7 Cpu 1200 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,480
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2014-2256 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data